/*
 * #%L
 * How to Continue from a Subdirectory with SimpleFileVisitor
 * $Id:$
 * $HeadURL:$
 * %%
 * Copyright (C) 2012 - 2015 Java Creed
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
package com.javacreed.examples.io;

import java.io.IOException;
import java.nio.file.FileVisitResult;
import java.nio.file.Path;
import java.nio.file.SimpleFileVisitor;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.Arrays;
import java.util.List;

public class CustomSimpleFileVisitor extends SimpleFileVisitor<Path> {

    private List<String> continueFrom;

    private Path rootPath;

    private FileVisitResult preVisitContinueFromResult = FileVisitResult.SKIP_SUBTREE;

    @Override
    public FileVisitResult preVisitDirectory(final Path dir, final BasicFileAttributes attrs) throws IOException {
        if (rootPath == null) {
            rootPath = dir;
            return FileVisitResult.CONTINUE;
        }

        if (preVisitContinueFromResult != FileVisitResult.CONTINUE) {
            if (continueFrom == null) {
                preVisitContinueFromResult = FileVisitResult.CONTINUE;
            } else if (rootPath.equals(dir)) {
                return FileVisitResult.CONTINUE;
            } else {
                final Path relative = rootPath.relativize(dir);
                final int index = relative.getNameCount() - 1;
                if (index < continueFrom.size()) {
                    final String dirName = dir.getFileName().toString();
                    final String name = continueFrom.get(index);

                    if (name.equals(dirName)) {
                        if (index == continueFrom.size() - 1) {
                            preVisitContinueFromResult = FileVisitResult.CONTINUE;
                        }

                        return FileVisitResult.CONTINUE;
                    }
                }
            }
        }

        return preVisitContinueFromResult;
    }

    public void setContinueFrom(final String... path) {
        continueFrom = Arrays.asList(path);
    }

    public void setRootPath(final Path root) {
        rootPath = root;
    }
}
